Lighting luminaire which is liquid cooled



March 12, 1968 J. c. KASTQVICH ET Al.

LIGHTING LUMINAIRE WHICH IS LIQUID COOLED 2 Sheets-Sheet 1 Filed Jan.12, 1966 March 12, 1968 J, c. KASTQVICH ET AL 3,372,740

LIGHTING LUMINAIRE WHICH IS LIQUID COOLED Filed Jan. 12, 1966 FIG. 4.

I RESERVOIR NGER 2 Sheets-Sheet United States Patent 3,372,740 LIGHTINGLUMTNAIRE WHICH IS LIQUID COOLED John C. Kastovich, Franklin Township,Belmont, and

Jack D. Meess, Franklin Township, Export, Pa., assignors to WestinghouseElectric Corporation, Pittsburgh, Pa., a corporation of PennsylvaniaFiled Jan. 12, 1966, Ser. No. 520,121 8 Claims. (Cl. 16547) Thisinvention relates generally to liquid-cooled luminaires and, moreparticularly, to an improved liquidcooled luminaire which is adapted foreasy connection to a liquid cooling system.

It is well known to provide unitary conduit systems formed by joiningtogether oppositely contoured halves of sheet metal. Such conduitsystems are known as Control Bond and Roll-Bond and have been used inconjunction with refrigerators as well as liquid-cooled luminaires. Inthe preferred form of the present invention such a conduit system isused to liquid cool luminaires and the conduit system is unitarilyformed in the luminaire reflector. It is necessary to provide conduitopenings which are readily adapted to be connected with supply andreturn liquid lines located in the service area above the luminaire. Itis difficult to make simple liquidtight connections between the conduitsin the reflector members and the liquid-containing service lines whichconnect to the cooled luminaire. Such connections must be readily madewithout stressing the material of which the luminaire is fabricated and,in addition, there frequently is only a small amount of space providedbetween the ceiling of the area to be illuminated and the floor above.It is also desirable to have access to the liquid-containing servicelines which connect to the luminaire without removing the luminaire fromits mounting in the ceiling.

It is therefore an object of this invention to provide a novelconduit-connecting arrangement for a liquid-cooled luminaire.

It is a further object of this invention to provide a novel conduitconnection for a liquid-cooled luminaire, which conduit connection canbe made without wrinkling the conduits or otherwise stressing thematerial of which the luminaire is fabricated.

It is another object to provide a liquid-cooled luminaire wherein readyaccess may be had to the service lines which connect to the luminairewithout removing the luminaire from its position in the ceiling.

Briefly these and other objects, which will become apparentas thedescription proceeds, are achieved by providing a luminaire having araised housing longitudinally disposed therealong for ballast andcircuit components. Reflecting cooling members which carry conduits areaflixed to either side of the housing. Securing flanges are providedalong the longitudinal edge of each cooling member adjacent to thehousing. Conduit extensions are provided extending laterally from eachcooling member into the housing. Each conduit extension terminates in aconduit opening. Conduits through which the cooling fluid has ingressand egress are provided for supplying and returning the cooling liquid.These conduits are connected to the conduit openings and extend throughthe raised portions of the housing.

The present invention will become more apparent when considered in viewof the following detailed description and drawings, in which:

FIGURE 1 is a perspective view of the present lurni naire;

FIG. 2 is a sectional view taken along lines II-II of FIG. 1;

3,372,749 Patented Mar. 12, 1968 FIG. 3 is an enlarged sectional topview taken along tines IIIIII of FIG. 2, with the middle portion of theluminaire broken away showing the conduit connections which are made inthe ballast housing;

FIG. 4 is an enlarged fragmentary view taken along lines IV-IV of FIG. 2showing the positioning of a connecting line with respect to thereflector; and

FIG. 5 is a perspective view of a modification of the luminaire as shownin FIG. 1, showing the cooling members connected in parallel to theservice lines.

Referring to FIG. 1, there is shown a luminaire 10 comprising agenerally horizontal and elongated housing 12 longitudinally disposedtherealong. A pair of generally similar cooling members 14 and 16 areprovided, each having a reflective lower surface. Each cooling membercomprises a top cover 18 having two longitudinal edges 18a and 18b, acurved depending side wall 20 afiixed to one of the longitudinal edges18a, and a securing flange 22 (better shown in FIG. 2) affixed to theother longitudinal edge 18b. The securing flanges 22 afiix the coolingmembers 14 and 16 to the housing 12 with the top covers 18 projectinggenerally horizontally away from the housing 12. End walls 24 areprovided at the ends of the cooling members 14 and 16, which inconjunction with the depending side walls 20 define a bottom lightopening 26 (better shown in FIG. 2).

Conduits 28 are preferably unitarily formed as a part of the coolingmembers 14 and 16 to enhance the heat conduction thereacross. Coolingliquid, such as water or ethylene glycol, for example, from a reservoir3t and pump means 31 (shown in block form in FIG. 2) is pumped into theconduits 28 through a supply conduit 32. The cooling liquid passesthrough the supply conduit 32 and exits from the luminaire 10 through areturn conduit 34. The cooling liquid then passes through a heatexchanger 36 (also shown in block form) and returns to the reservoir 30.The conduit means 32 and 34 extend through housing 12 and preferablyterminate in an upwardly extending rubber or flexible curved portion 35to facilitate connecting them to the supply and return lines locatedabove the luminaire 10. A plurality of luminaires It may be suppliedwith cooling liquid from a single reservoir 30. The preferred conduitspacing and the luminaire dimensions are described in more detail incopending application, entitled Liquid Cooled Luminaires, Ser. No.520,110, filed Jan. 12, 1966 concurrently herewith by the presentinventors and assigned to the present assignee.

FIG. 2 shows a solid light-transmitting closure member or light diffuser38 disposed over the bottom light opening 26 to form an enclosure 49with cooling members 14 and 16 and end walls 24. If desired, the lightdiffuser 38 may be infra-red absorbing or reflecting, to hinder heatfrom passing therethrough out of the luminaire 10. The luminaire 16preferably :is recessed into a ceiling 42 as shown, with the diffuser 38substantially flush with the lower surface thereof. if desired, a seal44 may be included around the bottom opening 26 engaging the peripheryof the light diffuser 36. The seal 44 prevents dust from entering theenclosure 40, and prevents warm air within the enclosure 40 from exitingtherefrom through the bottom opening 26. If the luminaire 10 is to be ofthe air handling type, the seal 44- will not be required. The enclosure40 contains heat generating discharge means or light sources 46,fluorescent lamps for example, supported by lampholders 48. The lightsources 46 have a predetermined input power rating, and generate heat aswell as light within the enclosure 40.

The securing flanges 22 are provided along substantially the entireinner longitudinal edge 18b of cooling members 14 and 16 adjacent to thehousing 12. Preferably, these flanges 22 are formed by bending the innerportions of the cooling members 14 and 16 downwardly. The securingflanges 22 are affixed to the spaced longitudinal sides 50 and 52respectively of housing 12. If desired, the securing flanges 22 may formthe lower portion of the housing 12 as shown in FIG. 2. A substantialsurface contact is made between the securing flanges 22 and the housinglongitudinal sides 50 and 52 to facilitate heat transfer therebetween.Preferably, circuit and ballast components 54 (shown in block form) arecontained in the housing 12. Preferably, both the housing 12 and theluminaire enclosure 40 are cooled by the cooling liquid flowing in theconduits 28, to remove a substantial part of the heat generated by boththe ballast components '4 and the light sources 46 respectively.Interconnecting webs 56 are provided between the adjacent portions ofthe conduits 28 in supporting and thermally conducting relationshiptherewith. The webs 56 and the conduits 28 comprise substantially all ofthe top covers 18 and the depending side walls 20. The inner surfaces 58of the webs 56 and conduits 28 are reflective and have a predeterminedarea which is disposed towards the light sources 46 to absorb the heatgenerated thereby. This heat is in turn conducted through the webs 56 tothe conduits 28, and carried away by the cooling fluid to the heatexchanger 36.

FIG. 3 shows two conduit extensions 58 and two conduit extensions 59positioned proximate each end of cooling members 14 and 16. Each coolingmember is provided with an inlet conduit extension and an outlet conduitextension. These conduit extensions 58 and 59 extend laterally into thehousing 12 through the raised portions of the longitudinal side walls 50and 52. The conduit extensions 58 and 59 terminate in conduit openings60 at the innermost edge thereof. If desired, the cooling members 14 and16 may be of identical construction as shown in FIG. 3, with the twoconduit extensions 58 and the two conduit extensions 59 positioned atthe corresponding ends directly across from one another. This identicalconstruction requires that the supply conduit 32 and return conduit 34both be offset as shown. At the other end of the cooling members 14 and16, the two conduit extensions 59 are connected by an interconnectingconduit 62. In this embodiment the conduit systems of each coolingmember 14 and 16 are connected in series with one another. As shown inFIG. 2, the top covers 18 are generally planar. The conduit extensions58 and 59 are generally coplanar with these top covers 18 and no bendingof the conduit extensions is required. Thus conduit weakening andwrinkling is eliminated.

FIG. 4 shows a conduit opening 60, and a securing flange 22. The flange22 extends substantially the entire length of the inner longitudinalboundary of cooling member 14. A similar flange is correspondinglypositioned on cooling member 16. In this embodiment the securing flanges22 are formed by bending down the inner longitudinal regions of thecooling members 14 and 16. The conduit extensions 58 and 59 are formedby the unbent portions of the securing flanges 22. A housing aperture 64is shown in the longitudinal side wall 50 of housing 12, through whichthe supply conduit 32 enters. Similar housing apertures are provided forthe return conduit 34 and the interconnecting conduit 62. Theseapertures 64 are located higher than the top cover 18, and are providedin that portion of the longitudinal side walls 50 and 52 which extendsabove the top covers 18.

FIG. 5 shows another embodiment of the present invention, in which theconduit systems of cooling members 14 and 16 are connected in parallel.Each cooling member is provided with a supply conduit 32a and a returnconduit 34a. The two supply conduits 32a are connected to the pump 31,and the two return conduits 34a are connected to the heat exchanger 36-.In this parallel modification, the pressure-head of cooling liquid whichis maintained across the luminaire is substantially less than thepressure-head in the series-connected preferred modification of FIG. 1.

As another possible embodiment, a valve 66 may be provided in one or allof the conduits 32 and 34 which traverse the ballast housing 12 as shownin FIG. 2. In this manner, proper flow rates for the cooling liquid canbe established without removing the luminaire from the ceiling. Ahousing bottom cover 68 is provided which is easily removed when thelight diffuser 38 is opened. This provides acess to the valve 66.Alternatively, the conduits can be readily drained without removing theluminaire from the ceiling. This facilitates easy access to the supplylines through the ballast housing without removing the luminaire fromits mounting in the ceiling.

It will be apparent to those skilled in the art that the objects of thisinvention have been achieved by providing a novel conduit connectingapparatus. Weakening and wrinkling have been avoided by extending theconduits laterally into a central ballast housing, with supply lineconnections extending through the ballast housing.

While a preferred embodiment of the invention has been illustrated anddescribed in detail, it is to be particularly understood that theinvention is not limited thereto or thereby.

We claim as our invention:

1. A luminaire adapted to be liquid-cooled to remove heat generated bylight-sources adapted to be supported therein, said luminairecomprising:

a generally horizontal and elongated housing longitudinally disposedalong said luminaire, said housing having spaced longitudinal sidewalls;

a pair of generally similar cooling members each having a reflectinglower surface, each of said cooling members comprising: a top coverhaving two longitudinal edges, a depending side wall afiixed to onelongitudinal edge of said top cover, and a securing flange affixed tothe other longitudinal edge of said top cover;

said securing flanges affixed to the longitudinal side walls of saidhousing with said top covers projecting generally horizontally away fromsaid housing on the opposite sides thereof, and a portion of eachlongitudinal side wall of said housing extending above said top covers;

end walls afiixed to the ends of said cooling members, a bottom lightopening defined by said end walls and said depending side walls;

a solid lighttrans1nitting closure member substantially covering saidlight opening;

spaced conduit means and interconnecting web members formingsubstantially .all of said top cover and said depending side wall ofeach of said cooling members, an inlet conduit extension formed on eachof said top covers and extending into said housing through the proximateone of the longitudinal side walls of said housing, said inlet conduitextension having a conduit inlet opening formed therein within saidhousing for the ingress of cooling liquid into said cooling members, anoutlet conduit extension formed on each of said top covers and extendinginto said housing through the proximate one of the longitudinal sidewalls of said housing, said outlet conduit extension having a conduitoutlet opening formed therein within said housing for the egress ofcooling liquid from said cooling members;

a cooling liquid supply conduit means connected within said housing toat least one of said conduit inlet openings, said supply conduit meansentering into said housing from the opposite side thereof as the saidinlet conduit extension to which said supply conduit means connects; and

a liquid return conduit means connected within said housing to at leastone of said conduit outlet openings, said return conduit means enteringinto said housing from the opposite side thereof as the said outletconduit extension to which said return conduit means connects, and saidsupply conduit means and said return conduit means entering into saidhousing at locations higher than said top cover.

2. The luminaire as specified in claim 1 wherein said securing flangesare in heat exchange relationship with the longitudinal sides of saidhousing, and heat generating ballast components are contained withinsaid housing.

3. The luminaire as specified in claim 1, wherein said top covers aregenerally planar and said conduit extensions formed thereon are coplanartherewith.

4. The luminaire as specified in claim 1, wherein said supply and returnconduit means enter into said housing through said longitudinal sidewalls, and exterior to said housing, said conduit means have a curvedfiexible upwardly extending portion.

5. The luminaire as specified in claim 1, wherein said securing flangescomprise the lower portions of the longitudinal side walls of saidhousing, and a bottom for said housing is afiixed to the lowerextremities of said securing flanges.

6. The luminaire as specified in claim 1, wherein an interconnectingconduit is provided between one outlet conduit opening of one of saidcooling members and one inlet conduit opening of the other of saidcooling members for serially connecting said spaced conduit means ofsaid cooling members between said supply conduit means and said returnconduit means.

7. The luminaire as specified in claim 1, wherein said housing has aremovable bottom cover, and a valve means is provided within saidhousing in at least one of said cooling liquid supply conduit means andsaid cooling liquid conduit return means.

8. A luminaire adapted to be liquid-cooled to remove heat generated bylight-sources adapted to be supported therein, said luminairecomprising:

a generally horizontal and elongated housing longitudinally disposedalong said luminaire, said housing having spaced longitudinal sidewalls;

a pair of generally similar cooling members each having a reflectinglower surface, each of said cooling members comprising: a top coverhaving two longitudinal edges, a depending side wall affixed to onelongitudinal edge of said top cover, and a securing flange afiixed tothe other longitudinal edge of said top cover;

said securing flanges afiixed to the longitudinal side walls of saidhousing with said top covers projecting generally horizontally away fromsaid housing on the opposite sides thereof, and a portion of each lon- 6gitudinal side wall of said housing extending above said top covers;

end walls afiixed to the ends of said cooling members, a bottom li htopening defined by said end walls and said depending side walls;

a solid light-transmitting closure member substantially covering saidlight opening;

spaced conduit means and interconnecting web members formingsubstantially all of said top cover and said depending side Wall of eachof said cooling members, an inlet conduit extension formed on each ofsaid top covers and extending into said housing through the proximateone of the longitudinal side walls of said housing, said inlet conduitextension having a conduit inlet opening formed therein within saidhousing for the ingress of cooling liquid into said cooling members, anoutlet conduit extension formed on each of said top covers and extendinginto said housing through the proximate one of the longitudinal sidewalls of said housing, said outlet conduit extension having a conduitoutlet opening formed therein within said housing for the egress ofcooling liquid from said cooling members;

a cooling liquid supply conduit means connected Within said housing toat least one of said conduit inlet openings, said supply conduit meansentering into said housing from the opposite side thereof as the saidinlet conduit extension to which said supply conduit means connects;

a cooling liquid return conduit means connected within said housing toat least one of said conduit outlet openings, said return conduit meansentering into said housing from the opposite side thereof as the saidoutlet conduit extension to which said return conduit means connects,and said supply conduit means and said return conduit means enteringinto said housing at locations higher than said top cover;

a cooling liquid reservoir and pump means connected to said supplyconduit means for supplying cooling liquid to said cooling members; and

a heat exchanger connected between said return conduit means and saidreservoir and pump means for removing heat from the cooling liquid.

References Cited UNITED STATES PATENTS 3,193,001 7/1965 Meckler 98-40ROBERT A. OLEARY, Primary Examiner. CHARLES SUKALO, Assistant Examiner.

1. A LUMINAIRE ADAPTED TO BE LIQUID-COOLED TO REMOVE HEAT GENERATED BYLIGHT-SOURCES ADAPTED TO BE SUPPORTED THEREIN, SAID LUMINAIRECOMPRISING: A GENERALLY HORIZONTAL AND ELONGATED HOUSING LONGITUDINALLYDISPOSED ALONG SAID LUMINAIRE, SAID HOUSING HAVING SPACED LONGITUDINALSIDE WALLS; A PAIR OF GENERALLY SIMILAR COOLING MEMBERS EACH HAVING AREFLECTING LOWER SURFACE, EACH OF SAID COOLING MEMBERS COMPRISING: A TOPCOVER HAVING TWO LONGITUDINAL EDGES, A DEPENDING SIDE WALL AFFIXED TOONE LONGITUDINAL EDGE OF SAID TOP COVER, AND A SECURING FLANGE AFFIXEDTO THE OTHER LONGITUDINAL EDGE OF SAID TOP COVER; SAID SECURING FLANGESAFFIXED TO THE LONGITUDINAL SIDE WALLS OF SAID HOUSING WITH SAID TOPCOVERS PROJECTING GENERALLY HORIZONTALLY AWAY FROM SAID HOUSING ON THEOPPOSITE SIDES THEREOF, AND A PORTION OF EACH LONGITUDINAL SIDE WALL OFSAID HOUSING EXTENDING ABOVE SAID TOP COVERS; END WALLS AFFIXED TO THEENDS OF SAID COOLING MEMBERS, A BOTTOM LIGHT OPENING DEFINED BY SAID ENDWALLS AND SAID DEPENDING SIDE WALLS; A SOLID LIGHT-TRANSMITTING CLOSUREMEMBER SUBSTANTIALLY COVERING SAID LIGHT OPENING; SPACED CONDUIT MEANSAND INTERCONNECTING WEB MEMBERS FORMING SUBSTANTIALLY ALL OF SAID TOPCOVER AND SAID DEPENDING SIDE WALL OF EACH OF SAID COOLING MEMBERS, ANINLET CONDUIT EXTENSION FORMED ON EACH OF SAID TOP COVERS AND EXTENDINGINTO SAID HOUSING THROUGH THE PROXIMATE ONE OF THE LONGITUDINAL SIDEWALLS OF SAID HOUSING, SAID INLET CONDUIT EXTENSION HAVING A CONDUITINLET OPENING FORMED THEREIN WITHIN SAID HOUSING FOR THE INGRESS OFCOOLING LIQUID INTO SAID COOLING MEMBERS, AN OUTLET CONDUIT EXTENSIONFORMED ON EACH OF SAID TOP COVERS AND EXTENDING INTO SAID HOUSINGTHROUGH THE PROXIMATE ONE OF THE LONGITUDINAL SIDE WALLS OF SAIDHOUSING, SAID OUTLET CONDUIT EXTENSION HAVING A CONDUIT OUTLET OPENINGFORMED THEREIN WITHIN SAID HOUSING FOR THE EGRESS OF COOLING LIQUID FROMSAID COOLING MEMBERS; A COOLING LIQUID SUPPLY CONDUIT MEANS CONNECTEDWITHIN SAID HOUSING TO AT LEAST ONE OF SAID CONDUIT INLET OPENINGS, SAIDSUPPLY CONDUIT MEANS ENTERING INTO SAID HOUSING FROM THE OPPOSITE SIDETHEREOF AS THE SAID INLET CONDUIT EXTENSION TO WHICH SAID SUPPLY CONDUITMEANS CONNECTS; AND A LIQUID RETURN CONDUIT MEANS CONNECTED WITHIN SAIDHOUSING TO AT LEAST ONE OF SAID CONDUIT OUTLET OPENINGS, SAID RETURNCONDUIT MEANS ENTERING INTO SAID HOUSING FROM THE OPPOSITE SIDE THEREOFAS THE SAID OUTLET CONDUIT EXTENSION TO WHICH SAID RETURN CONDUIT MEANSCONNECTS, AND SAID SUPPLY CONDUIT MEANS AND SAID RETURN CONDUIT MEANSENTERING INTO SAID HOUSING AT LOCATIONS HIGHER THAN SAID TOP COVER.